Sand-wheel.



T. NICHOLS.

SAND WHEEL.

APPLICATION FILED MAY 4, 1908.

946,920. Patented Jan. 18, 1910.

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THOMAS NICHOLS, OF GARDNER, MASSACHUSETTS, ASSIGNOR OF ONE-HALF TO I. G.

McKNIGI-IT, 0F GARDNER, MASSACHUSETTS.

SAND-WHEEL.

To all whom it may concern:

Be it known that I, THoMAs NIoHoLs, a citizen of the United States,residing at Gardner, in the county of Vorcester and State ofMassachusetts, have invented a new and useful SandfiVheel, of which thefollowing is a specification.

This invention relates toa sand wheel or other device for polishing andabrading.

The principal objects of the invention are to provide a simple andconvenient construction in which the sand-paper, emery-cloth, or othersheet material used for forming the desired operations shall be held insuch a way that there will be only a very narrow slot in the wheelthrough which the sheet passes and the rotation of the sand wheel or thelike, or other motion thereof for the purpose of sanding or polishingsurfaces can have no eifect to pucker or wrinkle the ma terial, anytendency in that direction being prevented by the taking up of thepolishing material, by means of a spring or the like, whereby the lifeof the sheet material, will be greatly prolonged, and its work made moreeven and effective; also to provide improved means for holding the sheetmaterial,

and improvements in details of construction thereof.

Further objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawing which shows certainforms in which the invention may be carried out, and in which Figure lis an end view of a portion of a sand wheel showing one form of theinvention; Fig. 2 is a plan of parts shown at the bottom of Fig. 1,illustrating the inside of the wheel; and Fig. 3 is a view similar toFig. 1 showing a modification.

This invention is illustrated as applied to that type of polishingdevices ordinarily termed sand wheels, although the invention may beused with any kind of polishing or abrading device, in which theoperations may be performed by means of a sheet of sand paper, emerycloth, or other material for polishing or abrading surfaces of wood,metal, or any other substance.

In many types of sand wheels the sand paper or other sheet material isheld rigidly at both ends, consequently as it stretches out tightly inuse, there is a tendency for the material to pucker up or gather in afold Specification of Letters Patent.

Application filed May 4, 1908.

Patented Jan. 18, 1910.

Serial No. 430,694.

as the wheel is rotated over the surface to be polished. This is verydestructive to the polishing sheet and results in wearing it out at oneend much quicker than elsewhere, so that the sheet has to be replacedlong before it is entirely worn out.

An important feature of this invention is to provide an efficient andconvenient means whereby the polishing material will not be subject tothis ditficulty, but will be kept smooth so that it will be worn outsubstantially uniformly from one end to the other, thus greatlyincreasing its durability.

In the form shown in Figs. 1 and 2, the invention is illustrated asapplied to a sand wheel comprising a cylindrical support or drum 10having a transverse slot 11 there through. On the inside of the wheeladja cent to the two sides of this slot are a pair of blocks 12 adaptedto be fixed in place by means of screws 13 or the like for holding asheet of padding 14 which may be of felt or any other materialordinarily used for this purpose. These two blocks hold the two ends ofthis padding rigidly in position. Mounted on the block on one side ofthe slot is another block 15 adapted to be held in position by any sortof a fastening device, as for example, a set of thumb screws 16 forrigidly holding the end of the sheet 17 of polishing or abradingmaterial such as sand-paper, emery-cloth, or the like. This sheetextends through the slot and around the drum, and is brought backthrough the slot and instead of being folded over on the other sidethereof, is brought across the slot over the end which is held by theblock 15. There it is held yieldingly in position. This yielding meansis shown in Figs. 1 and 2 as comprising a spring 20 held to the insideof the drum by a screw 21 or the like, and having on the opposite endthereof a plate 22. This plate has a jaw 23, and is provided with arivet or the like 24 substantially perpendicular to plate on which ispivoted a second plate 25. This plate has a jaw 26 cooperating with thejaw 23, and is provided with a guide pin 27 and a spring 28 for normallyholding the jaws closed. The pivot pin 24 is an exceedingly simpledevice for connecting these plates together, and although by itself itwould allow the jaws to swing laterally, this is prevented by the guidepin 27 which would be used any way to hold the spring 28. In use one endof the abrading sheet is fastened under the block 15 and the sheet isthen brought out through the slot and around the drum as has beendescribed, and may be inserted between the aws 23 and 26 simply byopening them by pressure on the rear of the plate 25.

The drum is rotated or otherwise moved in the direction of the arrow.This causes the end of the abrading material which is fastened by theblock 15 to advance ahead of the other end, and consequently any forcetending to stretch out and pucker up the abrading material will simplyresult in al lowing the spring 20 to pull the slack up into the insideof the drum so as to keep its operating surface smooth on the outside.This feature of having the rear or receding end of the materialyieldingly held so that the slack can be taken up is responsible for theincrease in the durability of the sheet.

By the employment of the principles of this invention another greatadvantage is secured, as the slit 11 through which the sheet materialpasses can be made much narrower than is the case with ordinaryconstructions. In fact it need be not much wider than the combinedthicknesses of the several sheets of abrading material and padding whichpass through, and yet the free end of the former can slip back and forthas occasion requires. This is an important feature, because some of theold forms of sand wheels necessarily have such a wide slit that theyleave marks at regular intervals on the work, showing where the sandpaper did not touch it.

\Vhile the construction above described is exceedingly simple andconvenient for accomplishing these purposes, yet it may be replaced byother forms, one of which is shown in Fig. In this form the spring 20 isconnected with a flat plate 80 on which is mounted a plate 31 adapted tobe fixed on the plate 30 by means of thumb-screws 82 or the like. Thetwo jaws formed at the end of these two plates perform the same ofiiceas the jaws 28 and 26 in the other form, but in this case the sheetcannot be inserted quite as readily in the jaws but they hold itpositively after it is fixed in position.

IVhile I have illustrated and described certain preferred forms of theinvention, I am aware that many modifications may be made therein by anyperson skilled in the art without departing from the scope of theinvention as expressed in the claims. Therefore, I do not wish to belimited in all respects to the details of construction, shown anddescribed, but

IVhat I do claim is 1. In a device of the class described, thecombination of a support having a slot, a

longitudinally extensible spring connected to the inside of the support,a plate connect ed with the spring and located between the spring andslot, and a pivoted jaw mounted on the plate.

2. In a device of the class described, the combination of a supporthaving a slot, a spring arranged along the inside of and connected tothe support, a plate connected with the spring, a pivoted jaw mounted onthe plate, and a second spring mounted on the plate between it and thejaw for yieldingly forcing said jaw toward the plate.

3. In a sand wheel, the combination of a cylindrical support having alongitudinal slit along one side thereof, fixed means on the inside ofthe support near said slit and 011 opposite sides thereof for holding asheet of padding material, fixed means on one side of said slit forholding the end of an abrasive sheet, and readily moving means on thesame side of the slit for holding the free end of said abrasive sheet,said movable means comprising a longitudinally extensible spring havingone end fixed directly to the inner wall of the drum at a distance fromthe slit and on the same side as said fixed support for the other end ofthe abrasive material, a plate in general alinement with said spring andsecured to one end thereof, said plate having a fixed jaw thereon, asecond jaw pivotally mounted on said plate and cooperating with thefixed jaw, and a spring mounted on said plate between it and the rear ofthe second jaw for normally holding said jaw closed against the firstnamed jaw.

4:. In a device of the class described, the combination with a support,of a spring .connected with said support, a plate connected with thespring and having a aw thereon, a second plate. a rivet perpemlicular tosaid plates by which said plates are pivoted together, said second platehaving a jaw cooperating with the first named jaw, and a spring forforcing said aws together.

In an article of the class described, the combination of a rotarysupport having a slot, a pair of blocks inside the support on oppositesides of the slot for holding a sheet of padding in fixed position onthe outside of the support, a second block on one of said blocks forfixedly holdii'ig the end of a sheet of abrading or polishing material,and yielding means for holding the other end of the sheet of abrading orpolishing material.

In testimony whereof I have hereunto set my hand, in the presence of twosubscribing witnesses.

THOMAS NICHOLS.

Vitnesses 1 VA A. STEWART, CATHERINE M. CLANoY.

